Add support for SimpliSafe system notifications

[bachya]

Proposed change

This PR adds support for SimpliSafe system notification (firmware updates, etc.). These notifications will fire SIMPLISAFE_NOTIFICATION events with this data:

• category: The notification category (e.g., error)
• code: The SimpliSafe code for the notification
• notification_text: The actual text of the notification
• timestamp: The UTC timestamp of the notification

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example entry for configuration.yaml:

# Example configuration.yaml
simplisafe:
  accounts:
    - username: !secret simplisafe_username
      password: !secret simplisafe_password

Additional information

• This PR fixes or closes issue: N/A
• This PR is related to issue: N/A
• Link to documentation pull request: Add docs for SimpliSafe system notifications home-assistant.io#12115

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[codecov]

Codecov Report

Merging #31936 into dev will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev   #31936   +/-   ##
=======================================
  Coverage   94.67%   94.67%           
=======================================
  Files         763      763           
  Lines       55239    55239           
=======================================
  Hits        52295    52295           
  Misses       2944     2944           

Impacted Files	Coverage Δ
...ssistant/components/islamic_prayer_times/sensor.py	94.68% <0.00%> (-1.07%)	⬇️
homeassistant/helpers/entity_registry.py	99.53% <0.00%> (ø)	⬆️
homeassistant/components/uk_transport/sensor.py	94.20% <0.00%> (+0.72%)	⬆️

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[springstan]

LGTM ✌ thanks for implementing my suggested change :)